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Power Electronics
Of many possibilities, we first explore the simple system which avoids transferring power to the moving shuttle, so that the field travels, and the armature winding stays stationary.
This then raises the question of how to drive the armature, since it would be wasteful and difficult to excite its entire length at one time. So we consider sectioning the armature. In fact given the inductances and the switching speed it really isn’t an option to excite the whole length. There is also the issue of the number of phases. 3 is magic number for rotating fields, but there nothing special about three for a linear machine, in fact for the systems studied via VTB the number will be rather higher. For example if we divide the track into 10 sections and use 10 phases, we would need some 200 phase legs to do the switching. With this come a very high level of fault / damage tolerance. Losing a section of the track, or indeed 10 phase legs, leaves the rest of the system functional, and with the control envisaged a very high level of operational readiness is possible. This is one of the great strengths of an electric system, and warrants extensive study via simulation, under a range of
damage / fault scenarios. This also reinforces the value of the VTB study.
Shuttle Simulation Video
Blade Shuttle (transparent) (910 KB)
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